1. Field of the Invention
The present invention generally relates to an electrical connector, and more particularly to an electrical connector for removably mounting a chip module to a printed circuit board.
2. Description of Related Art
Connectors for mounting a chip module, such as a Central Processing Unit (CPU), to a printed circuit board are widely used in electrical equipments. Such a connector usually includes a base, a plurality of contacts retained in the base, a fastening frame partially surrounding the housing, a metal clip and an operational lever attached to the fastening frame. The base has a mounting surface to which the chip module is mounted and a connecting surface attached to the printed circuit board. When mounting, the connector is mounted to the printed circuit board, then the chip module is assembled to the mounting surface of the base and the metal clip is rotatably to partially cover the chip module, finally rotating the operational lever to a close position for retaining the chip module to the base. The contacts retained in the base realize the electrical connection between the chip module and the printed circuit board.
However, the connector with above structures has at least the shortcomings as follows: After securing the metal clip to the chip module, an upward force produced by the stiffener is exerted to the base since the base is put on the stiffener, and the clip and the lever are respectively pivotally retained to opposite ends of the stiffener. Particularly, the upward force becomes small gradually as away from opposite ends of the stiffener. Therefore, opposite ends of the base may become curved and thus, causing bottom surface of the base concave and influencing electrical connection between the electrical chip and the printed circuit board.
Therefore, it is desired to provide an improved electrical connector to stress the problems mentioned above. It is noted that U.S. Pat. No. 7,179,092 discloses one solution while such solution is somewhat passive from the technical viewpoint.